Question

好的，所以我做了一个java程序，你从用户输入石头纸或剪刀，然后计算机将生成随机选择，并相应地打印结果。程序逻辑（我的意思是用户和对手选择的比较）工作正常。我设置了一个do-while循环，用户输入'Y'然后会有第二个匹配，这将持续到用户终止循环。但是，我收到错误“无法找到符号：变量ans”

所以有人可以解释一下，为什么我会收到这个错误以及如何修复它？

以下是代码：

import java.lang.Math;

import java.util.Scanner;

公共类STP

 {      
      public static void main (String args[])
             {
                 do {
                 String c , ans ;

                    Scanner in = new Scanner(System.in);
                    System.out.println("Stone , Paper or Scissor ?");
                    System.out.println("Press s for stone , p for paper and sc for scissor ");
                    System.out.println("Enter Your Choice");
                    c=in.nextLine();
                              int max,min=0;
                              int rand = 0;
                              max=3;
                              min=1;
                              rand= min +(int)(Math.random() * ((max-min)+1));
                              System.out.println("Rand = " + rand);

                                     switch(c)
                                       {
                                       case "s" :
                                       if (rand==1){
                                         System.out.println("User's Choice : Stone");
                                         System.out.println("Opponent's Choice : Stone");
                                         System.out.println("Draw!"); } 

                                      else if (rand==2){
                                         System.out.println("User's Choice : Stone");
                                         System.out.println("Opponent's Choice : Paper");
                                         System.out.println("Opponent Wins!"); } 

                                       else if (rand ==3){
                                         System.out.println("User's Choice : Stone");
                                         System.out.println("Opponent's Choice : Scissor");
                                         System.out.println("User Wins!"); } 
                                         break;

                                               case "p":
                                               if (rand==1){
                                                 System.out.println("User's Choice : Paper");
                                                 System.out.println("Opponent's Choice : Stone");
                                                 System.out.println("User Wins!");}

                                              else if (rand  ==2){
                                                 System.out.println("User's Choice : Paper");
                                                 System.out.println("Opponent's Choice : Paper");
                                                 System.out.println("Draw!");}  

                                              else if (rand == 3){
                                                 System.out.println("User's Choice : Paper");
                                                 System.out.println("Opponent's Choice : Scissor");
                                                 System.out.println("Opponent Wins!!");}
                                                 break;
                                                      case "sc":
                                                      if (rand==1){
                                                         System.out.println("User's Choice : Scissor");
                                                         System.out.println("Opponent's Choice : Stone");
                                                         System.out.println("Opponent Wins!!");}

                                                      else if (rand==2){
                                                          System.out.println("User's Choice : Scissor");
                                                          System.out.println("Opponent's Choice : Paper");
                                                          System.out.println("User Wins!");}

                                                       else if (rand==3){
                                                           System.out.println("User's Choice : Scissor");
                                                           System.out.println("Opponent's Choice : Scissor");
                                                           System.out.println("Draw!!");}
                                                       break;
                                                          }
                                     System.out.println("--------------------------------------------------------------------------------------------------------------------");
                                     System.out.println("Do you want to play again ? ");
                                     System.out.println("Enter 'Y' for Yes and 'N' for No");
                                     ans = in.nextLine();
                                                       }
                                     while (ans =="Y");                  
                                                    }
                                                }

Answer 1

必须在while循环之前声明

ans才能处于循环条件的范围内。您还应该将字符串比较从==更改为等于。

             String ans = "";
             do {
                 String c;
                 ...
             } while (ans.equals("Y"));

使用Java的岩石纸剪刀游戏

1 个答案: